The field of this invention is vascular disease, particularly vascular diseases characterized by the presence of calcified vascular occlusions.
Vascular occlusions, which may be partial or total occlusions, play a prominent role in many types of vascular disease. Many vascular occlusions encountered in the treatment of vascular disease are characterized by having a mineral component, i.e. they are calcified. Calcified vascular occlusions, both partial and total, are found in both peripheral and coronary vascular disease.
A variety of different protocols have been developed for treating vascular diseases characterized by the presence of partial or total occlusions. Such treatment methodologies generally involve mechanical removal or reduction of the size of the occlusion, and include: bypass surgery, balloon angioplasty, mechanical debridement, atherectomy, and the like.
Despite the plethora of different treatment strategies that have been developed for the treatment of vascular diseases associated with vascular occlusions, there are disadvantages associated with each technique, such as tissue damage, invasiveness, etc. For example, restenosis is a common complication that results in arteries in which occlusions have been mechanically removed.
Calcified vascular occlusions pose significant challenges to currently employed treatment methodologies. For example, where the target vascular occlusion is a total occlusion, it is difficult if not impossible to pass a guidewire through the occlusion, which step is required for many of the currently used procedures. While bypass grafts are sometimes available as alternatives in such instances, bypass procedures have their own risks and complications. Furthermore, if there is no appropriate anastomosis site available, amputation is often the only alternative.
As such, there is continued interest in the development endovascular methods of treating vascular occlusions. Of particular interest would be the development of methods and devices suitable for use in the treatment of calcified vascular occlusions.
Relevant Literature
U.S. Patents of interest include: U.S. Pat. Nos. 4,445,892; 4,573,966; 4,610,662; 4,636,195; 4,655,746; 4,690,672; 4,824,436; 4,911,163; 4,976,733; 5,059,178; 5,090,960; 5,167,628; 5,195,955; 5,222,941; 5,370,609; 5,380,284; 5,443,446; 5,462,529; 5,496,267 and 5,785,675. See also: Koltun et al., Arch. Surg. (August 1987) 122:901-905; Olin et al., Ann. Emerg. Med. (November 1988) 17:1210-1215; Hargrove et al., Surgery (December 1982) 92:981-993; and Rickard et al., Cardiovascular Surg. (December 1997) 5:634-640. See also Peripheral Endovascular Interventions, 2nd ed. (White and Fogarty eds., Springer, N.Y.)(1996) pp 565-576.
Catheter systems and methods are provided for enhancing fluid flow, i.e. blood flow, through a vascular site occupied by a vascular occlusion. The subject catheter systems include at least an aspiration catheter and at least one of a total occlusion insert catheter and a partial occlusion insert catheter, where the insert catheters are capable of being slidably moved within the aspiration lumen of the aspiration catheter. In practicing the subject methods, a surface of the vascular occlusion is flushed with an acidic dissolution fluid using the subject catheter systems for a period of time sufficient for fluid flow through the vascular site to be enhanced, e.g. increased or established. The subject catheter systems and methods find use in the treatment of a variety of different vascular diseases characterized by the presence of calcified vascular occlusions, including peripheral and coronary vascular diseases.